Yes, you can switch from a Medicare Supplement to Medicare Advantage, but the timing and your health matter

You can move from a Medigap policy (Medicare Supplement) to Medicare Advantage at any time, but the process and your options depend on when you make the change. If you switch during the annual Medicare Open Enrollment Period — October 15 to December 7 each year — your new Medicare Advantage plan takes effect January 1. If you switch outside that window, you may face waiting periods or be unable to join a plan until the next enrollment period, depending on your situation.

The bigger consideration is that Medicare Advantage plans use medical underwriting in some states, meaning they can review your health history and deny you coverage or charge more. Medicare Supplement plans cannot do this — they must accept you at standard rates during certain windows. Once you drop your Medigap policy, getting back into one later may be harder and more expensive, especially if you have developed new health conditions.

Key Takeaways

  • You can switch to Medicare Advantage during Open Enrollment (October 15 to December 7) with a January 1 effective date, or outside that window if you have a may have access to life event.
  • Medicare Advantage plans may review your health history and deny coverage in some states, while Medicare Supplement plans must accept you at standard rates during open enrollment and certain windows.
  • If you drop your Medigap policy and later want to return to it, you may lose may provide-issue rights and face higher premiums or denial, depending on your state and how long you were without coverage.
  • Medicare Advantage typically costs less in monthly premiums but has network restrictions, copays per visit, and annual out-of-pocket limits; Medigap costs more upfront but covers most costs after Medicare pays its share.

When you can make the switch

The easiest time to switch is during the annual Medicare Open Enrollment Period, which runs October 15 to December 7 each year. During this window, you can drop your Medigap plan and enroll in any Medicare Advantage plan available in your area without restrictions. Your new plan begins January 1.

You can also switch outside Open Enrollment if you have a may have access to life event — such as moving out of your plan's service area, losing employer coverage, or experiencing a significant change in income. These events trigger a Special Enrollment Period, usually lasting 60 days, during which you can change plans. Contact Medicare at 1-800-MEDICARE or visit Medicare.gov to report a may have access to event and confirm your may be able to access window.

If you try to switch outside Open Enrollment without a may have access to event, your request will be denied and you will remain in your current Medigap plan until the next October 15.

Health underwriting and the risk of being denied

This is the critical difference between the two plan types. Medicare Supplement plans cannot deny you or charge you more based on your health — they must accept you at the same standard rates as anyone else during Open Enrollment and during certain may provide-issue windows (such as within 63 days of losing employer coverage). Medicare Advantage plans, however, can and do review your medical history in many states.

In some states, Medicare Advantage plans have the right to deny your enrollment if you have certain pre-existing conditions or complex medical needs. In other states, they must accept you but may charge higher premiums. This varies by state and by plan, so you cannot assume you will be accepted. Before you drop your Medigap policy, contact the Medicare Advantage plan directly and ask whether they will accept you given your health history.

If a Medicare Advantage plan denies you, you will still have your Medigap policy in place — but if you have already cancelled it, you may not be able to get back into one at a standard rate, especially if you have developed new conditions since you left.

What happens if you want to switch back to Medigap later

Switching back from Medicare Advantage to a Medicare Supplement is possible, but it is not always straightforward or affordable. If you drop your Medigap policy to join Medicare Advantage, you lose your may provide-issue rights in most states. This means that when you try to buy a new Medigap policy later, the insurance company can deny you, charge you more, or exclude coverage for pre-existing conditions — depending on your state's rules and how long you have been without Medigap coverage.

Some states offer a one-time right to return to Medigap without underwriting if you have been in Medicare Advantage for less than one year and are switching back during Open Enrollment. Other states have no such protection. Before you switch to Medicare Advantage, contact your state's insurance commissioner's office or your Medigap insurer to learn what protections exist in your state if you change your mind later.

The longer you stay in Medicare Advantage, the harder it becomes to return to Medigap at an affordable rate. This is one reason many people stay with Medigap even though the monthly premium is higher — the flexibility to switch back is worth the cost.

Cost differences: premiums, copays, and out-of-pocket limits

Medicare Advantage typically has a lower or zero monthly premium but requires you to pay copays at each doctor visit, specialist visit, and for prescriptions. You also have an annual out-of-pocket maximum — once you reach it, the plan covers 100% of in-network costs for the rest of the year. In 2024, this maximum varies by plan but is capped by Medicare at a certain amount (the exact figure changes yearly).

Medicare Supplement (Medigap) has a higher monthly premium — often $100 to $300 or more, depending on your age and the plan letter you choose — but once you meet your deductible (if any), the plan covers most of what Medicare does not pay. You typically have no copays for doctor visits or hospital stays. You pay the full cost of anything Medicare does not cover, such as dental, vision, or hearing aids.

The right choice depends on how often you see doctors and specialists. If you are generally healthy and see a doctor once or twice a year, Medicare Advantage may cost less overall. If you have multiple chronic conditions and see many specialists, Medigap may save you money despite the higher premium.

Network restrictions and coverage area

Medicare Advantage plans have service areas — they only cover care from doctors and hospitals within a specific geographic region, usually a county or group of counties. If you move outside that area, you may lose coverage or have to switch plans. Some Medicare Advantage plans are HMOs (requiring you to use in-network providers) and others are PPOs (allowing out-of-network care at a higher cost).

Medicare Supplement plans have no network restrictions. You can see any doctor or hospital in the United States that accepts Medicare, and you can move anywhere without losing coverage. This flexibility is especially valuable if you travel frequently, split time between two homes, or think you might move in the next few years.

Before switching to Medicare Advantage, confirm that your current doctors and hospitals are in the plan's network. If your primary care doctor is not, you will have to choose a new one or pay out-of-network rates.

Steps to switch from Medigap to Medicare Advantage

If you decide to switch during Open Enrollment, start by reviewing the Medicare Advantage plans available in your area. Visit Medicare.gov, use the Plan Finder tool, and enter your zip code to see all plans, their premiums, networks, and coverage details. You can also call 1-800-MEDICARE and ask for a list of plans in your area.

Next, contact the Medicare Advantage plan you want to join and confirm that your doctors and hospitals are in-network and that the plan will accept you given your health history. Ask about the monthly premium, copays, deductibles, and annual out-of-pocket maximum. Once you have chosen a plan, you can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or by mail using the enrollment form.

At the same time, contact your Medigap insurer and ask how to cancel your policy. Tell them your cancellation date — it should be December 31 so that your Medicare Advantage plan takes effect January 1 with no gap in coverage. Some insurers require written notice; others allow cancellation by phone. Confirm the cancellation in writing and keep a copy for your records.

Frequently Asked Questions

Can Medicare Advantage plans deny me because of my health?

In some states, yes. Medicare Advantage plans can review your health history and deny enrollment or charge higher premiums, depending on state law and plan rules. Medicare Supplement plans cannot do this during may provide-issue periods. Before you drop your Medigap policy, contact the Medicare Advantage plan and ask directly whether they will accept you.

What if I switch to Medicare Advantage and then want to go back to Medigap?

You can switch back, but you may lose may provide-issue rights and face denial or higher premiums. Some states offer a one-time right to return without underwriting if you switch back within one year. Check your state's rules before you make the switch.

Do I have to switch during Open Enrollment?

No. If you have a may have access to life event — such as moving, losing employer coverage, or a significant income change — you can switch during a Special Enrollment Period. Otherwise, you must wait for Open Enrollment (October 15 to December 7) to make the change.

Will my doctors accept Medicare Advantage?

Most do, but not all. Before you enroll, use the plan's provider search tool or call the plan directly to confirm that your primary care doctor, specialists, and preferred hospital are in-network. If they are not, you will have to choose new providers or pay out-of-network rates.

Is Medicare Advantage cheaper than Medigap?

Usually the monthly premium is lower, but you pay copays at each visit. If you are healthy and see a doctor rarely, Medicare Advantage may cost less overall. If you have multiple chronic conditions and see many specialists, Medigap may save you money despite the higher premium.